Wye or Delta motor connected to Wye or Delta power supply ?

Discussion in 'General Electronics Chat' started by scriverman, Mar 28, 2011.

  1. scriverman

    Thread Starter New Member

    Jan 25, 2011
    Do you have to match configuration wye or delta of motor to power source or is a motor an inherently balanced load and 3 phase power is 3 phase power? You have phase to phase to phase ie L1 to T1, L2 to T2 and L3 to T3 then ground to ground with no neutral terminal or Line connection to carry unbalanced current because the motor windings should be balanced.

    And the only reason you need to know if a motor is actually a Wye or Delta configuration is for dual voltage motors you have to configure the 9 leads for low vs high voltage and or if you have to remark the wires.

    I am assuming phase to phase to phase voltage is correct.


    I don't think a motor will have a neutral leg just T1,T2,T3 and ground. Therefore, you don't have to worry about phase to neutral voltage.

    When I look in Grainger the motors just list 3 phase and voltages but don't list wether or not they are Delta vs Wye wound.
  2. BillB3857

    Senior Member

    Feb 28, 2009
  3. scriverman

    Thread Starter New Member

    Jan 25, 2011
    BillB I think I understand that part. The lead connections low vs high voltage is often on the side of the motor.

    But does the motor configuration Y/Delta have to match the power source configuration?

    This may be a bad example of voltages but ....
    If I have a 208V 3phase 4 wire power source (wye) can I use a dual voltage 3 phase delta wound motor and configure for low voltage and connect it to the system and it work assuming the low voltage motor configuration was ok at 208V.

    Since I have 208V from A-B-C and I don't connect a neutral connection does the motor care if 208V L1-L2-L3 is a wye source for a delta wound motor ?????? Or does it have to be a 3 wire or 4 wire Delta source for power for the Delta wound motor????
  4. t_n_k

    AAC Fanatic!

    Mar 6, 2009
    The 4-wire power supply would not be troubled by a well balanced delta load. Provided the motor delta windings are rated for the supply voltage input, and the supply can accommodate the motor load current there should be no issues.
  5. GetDeviceInfo

    Senior Member

    Jun 7, 2009

    The thing that matters is that you match your voltage. If your motor is 230v, you'll need to add 10% to your current calculations, including wire size, overloads, and over currents. I've seen several times where service and protection is based on the nameplate 230v, but the motor ends up on a 208v and gives grief, both in operation and in upgrading.